JP2000212360A - Fluororesin composition for coating fluorescent lamp, coating material and fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluororesin composition capable of blocking ultraviolet rays radiated from a fluorescent lamp, excellent in durability and useful as a fluorescent lamp coating material by adding complex particles consisting of aggregates of specific zinc oxide particles. SOLUTION: This composition contains complex particles consisting of aggregates of zinc oxide particles coated with amorphous silica. It is preferable that the complex particles consists of aggregates of zinc oxide particles prepared by coating 100 pts.wt. of zinc oxide with 20-200 pts.wt. of amorphous silica, they have particle sizes of 0.1-30 μm, and the fluororesin is a homopolymer of tetrafluoroethylene, a homopolymer of chlorotrifluoroethylene, a tetrafluoroethylene-ethylene copolymer or the like. The complex particles may be obtained, for example, by coating an insoluble zinc compound such as zinc hydroxide with amorphous silica and baking the obtained particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluororesin composition for fluorescent lamp covering, which blocks ultraviolet rays emitted from a fluorescent lamp and has excellent durability, a fluorescent lamp covering material, and a fluorescent lamp coated with the material. .

[0002]

2. Description of the Related Art In the display of goods and the like, articles are faded by ultraviolet rays of a fluorescent lamp, and foods are deteriorated. Insects fly to goods and foods by sensing the ultraviolet light emitted by the fluorescent light. Furthermore, a large number of insects fly to streetlights and vending machine lighting, causing discomfort. To prevent insects from flying,
It is necessary to block ultraviolet rays having a wavelength of 330 to 360 nm generated from a fluorescent lamp.

[0003] As a method of blocking a specific light wavelength of a fluorescent lamp, a resin containing an ultraviolet absorber is used to block 380 to 40.
Method for effectively blocking 0 nm wavelength (Japanese Patent Laid-Open No. 8-315)
778, JP-A-9-73878). However, since the resin used is a non-heat-resistant material such as polyvinyl chloride and polyester, deformation such as wrinkles due to heat occurs near the light source of a fluorescent lamp, and the effect cannot be maintained for a long time.

On the other hand, fluororesins have excellent heat resistance and transparency, and are widely used as agricultural house films, roof materials and the like. In addition, since the fluororesin has elasticity, it is considered that when coated with a fluorescent lamp, even if an accident such as a breakage of the fluorescent lamp occurs, the fragments of the fluorescent lamp can be prevented from scattering.

[0005] Conventionally, as a method of imparting an ultraviolet blocking function to a fluororesin film itself, a tetrafluoroethylene (hereinafter referred to as TFE) -ethylene polymer (hereinafter referred to as E
A method has been proposed in which titanium oxide or zinc oxide having a particle diameter of about 0.02 μm is blended with TFE) (JP-A-7-3047). However, in this method, the dispersibility of the titanium oxide fine particles is poor, and there is a problem that the fine particles aggregate and the film becomes white.

Further, a method is disclosed in which a titanium oxide fine particle surface-coated with a silane coupling agent having a methyl group bonded to a silicon atom is dispersed and kneaded in ETFE to produce an ultraviolet shielding film (JP-A-7-1995). 30492
4). An ETFE film to which a small amount of titanium oxide is added can block ultraviolet rays having a short wavelength of at least 300 nm or less, but in order to block ultraviolet rays having a wavelength of 360 nm or less, it is necessary to increase the amount of titanium oxide added. When the amount of titanium oxide is large, the dispersibility of the surface-treated titanium oxide is not improved, and a film having a small haze cannot be obtained.

[0007] Zinc oxide has a better ultraviolet blocking function than titanium oxide.
The TFE film can block ultraviolet light having a wavelength of 360 nm or less. However, zinc oxide reacts with a fluorine compound released from a fluororesin during outdoor exposure and is transformed into zinc fluoride having no ultraviolet ray blocking function. As a result, there is a problem that the ultraviolet ray blocking function of the ETFE film tends to be reduced. Also,
Even when zinc oxide fine particles are kneaded with ETFE to form a film, the film is easily deteriorated by the generated fluorine compound.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a fluororesin composition for fluorescent lamp coating, a film or tube of the fluororesin composition, and a coating material for fluorescent lamps which blocks ultraviolet rays of 360 nm or less and has excellent durability. , And a fluorescent lamp coated with the material.

[0009]

SUMMARY OF THE INVENTION The present invention provides a fluororesin composition for coating a fluorescent lamp, comprising composite particles obtained by assembling zinc oxide particles coated with amorphous silica. Also,
A material for covering a fluorescent lamp, comprising a film or a tube of the fluororesin composition is provided. Also provided is a fluorescent lamp coated with the coating material.

The fluororesin composition of the present invention comprises zinc oxide 1
A particle size of 0.1 to 0.2 parts by weight of zinc oxide particles coated with 20 to 200 parts by weight of amorphous silica
It is preferable to include composite particles of about 30 μm.

The composite particles according to the present invention include, for example,
It can be produced by calcining particles obtained by coating an insoluble zinc compound with amorphous silica. The insoluble zinc compound is a zinc compound that is insoluble or hardly soluble in water, and examples thereof include zinc hydroxide, zinc phosphate, zinc carbonate, and zinc oxide.

Amorphous silica is amorphous silica having no crystallinity, for example, sodium silicate No. 3 (SiO 2).
₍₂ content: 28.5%) and amorphous silica obtained by hydrolyzing a silicon compound such as tetraethylsilicate.

Specific examples of the production of the composite particles are shown below. For example, zinc oxide having a particle size of about 0.01 μm is dispersed in water, and a silicon compound is dropped into this aqueous dispersion with stirring,
Thereafter, a method of drying and further baking at 200 to 1000 ° C., preferably 400 to 600 ° C. may be mentioned. Further, water is added to an insoluble zinc compound such as zinc carbonate to form an aqueous dispersion using a disperser or an emulsifier, and a silicon compound is dropped into the aqueous dispersion with stirring, and silica having a particle size of about 0.01 μm or less is used. A coated insoluble zinc compound is obtained. Then, after that, it is dried and preferably at 200 to 1000 ° C, preferably 400 to 600 ° C.
By firing at ℃, the insoluble zinc compound becomes zinc oxide, and a composite particle in which sub-oxide particles coated with amorphous silica are aggregated is obtained.

Next, powder particles are formed using a mixer such as a Henschel mixer, a crusher, a crusher, or the like. Although the particle size after crushing is not particularly limited, the average particle size is not more than 0.1.
The range is preferably from 1 to 30 μm, more preferably from 4 to 10 μm. If the particle diameter is smaller than 0.1 μm, the particles become bulky and difficult to handle when kneading with a fluororesin. If it is larger than 30 μm, holes are likely to be formed in the coating material composed of a film or a tube.

The composite particles are particles in which amorphous silica coated with insoluble zinc compound particles is fused and solidified in the drying and firing steps during the production of the composite particles.
Since the insoluble zinc compound particles and zinc oxide particles before firing are covered with amorphous silica, the insoluble zinc compound particles and zinc oxide particles are less likely to undergo secondary aggregation and tertiary aggregation. The aggregate of the particles in the composite particles used in the present invention is the one in which ultrafine particles of uncoated zinc oxide of 0.01 μm or less conventionally used to secure good transparency are subjected to secondary aggregation or tertiary aggregation. different. Since the coated amorphous silica in the present invention has high transparency, it is 0.1 to 30 μm.
Does not adversely affect the transparency of the coating material.

In the composite used in the present invention, since the thickness of the amorphous silica coating the zinc oxide is large, the zinc oxide does not come into contact with the fluororesin, and reacts with the fluorine compound generated from the fluororesin to form the fluoride. Deterioration to zinc can be prevented.

The insoluble zinc compound coated with amorphous silica is also oxidized in the firing step, and finally most of the insoluble zinc compound is changed to zinc oxide, so that it has the same effect as zinc oxide.

The amorphous silica is used in an amount of 20 to 200 parts by weight, preferably 50 to 150 parts by weight, per 100 parts by weight of zinc oxide.
Parts by weight. If less than 20 parts by weight, the coating thickness of the amorphous silica is small, so that it is difficult to prevent the zinc oxide from being altered by the fluorine compound generated in the fluororesin for a long time,
If it exceeds 200 parts by weight, the ultraviolet blocking performance is small.

In order to improve the dispersion of the composite particles in the fluororesin, the surface of the composite particles is preferably subjected to a hydrophobic treatment with a surface treating agent. Since the composite particles used in the present invention have a particle size of 0.1 to 30 μm, surface treatment can be easily performed.

As the surface treating agent, any agent capable of firmly bonding to the surface of the composite particles and making it hydrophobic can be used, and a hydrolyzable group such as an alkoxy group, a hydroxyl group, an isocyanate group, or a chlorine atom, particularly a carbon number Organosilicon compounds in which two or three alkoxy groups are directly bonded to two or three silicon atoms are preferably used. More preferably, an organosilicon compound having such a hydrolyzable group and further having a hydrophobic organic group bonded to a silicon atom through a carbon-silicon bond is used, such as a silane coupling agent or silicone oil. Are preferred.

A general silane coupling agent has a hydrolyzable group and a non-hydrolyzable organic group, and the non-hydrolyzable organic group has a functional group such as an epoxy group or an amino group. . Such a functional group has high hydrophilicity, and is not so preferable as the surface treatment agent in the present invention. Rather, an organic silicon compound having, as an organic group, a hydrocarbon group having no hydrophilic group or a fluorinated hydrocarbon group providing high hydrophobicity is preferred.

As the organic group bonded to the silicon atom through a carbon-silicon bond, an alkyl group, an alkenyl group, an aryl group, a mono (or poly) fluoroalkyl group, a mono (or poly) fluoroaryl group and the like are preferable. In particular, it may be substituted with an alkyl group having 2 to 20 carbon atoms, a mono (or poly) fluoroalkyl group having 2 or more carbon atoms having one or more fluorine atoms, an alkyl group or a mono (or poly) fluoroalkyl group. A phenyl group and the like are preferred.

The organosilicon compound may be an organosilicone compound in which a hydrolyzable group is directly bonded to a silicon atom. The organic group in the organosilicone compound is preferably an alkyl group having 4 or less carbon atoms or a phenyl group. As such an organosilicone compound, a compound called silicone oil can be used.

Specific examples of the organosilicon compound include trialkoxysilanes such as isobutyltrimethoxysilane, hexyltrimethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane and ethyltriethoxysilane, and dimethyl silicone. Oils, silicone oils such as methyl hydrogen silicone oil and phenylmethyl silicone oil are preferred, and isobutyltrimethoxysilane, hexyltrimethoxysilane, ethyltriethoxysilane and dimethylsilicone oil are particularly preferred. The method of the surface treatment is not limited, but a method of dispersing the composite particles in a solution of a surface treatment agent, such as water, alcohol, acetone, or n-hexane, and then drying the dispersion is preferable.

The fluororesin in the present invention is not particularly limited, but may be TFE homopolymer, chlorotrifluoroethylene (hereinafter referred to as CTFE) homopolymer, ETFE, T
FE-perfluoro (alkyl vinyl ether) copolymer (hereinafter, referred to as PFA), TFE-hexafluoropropylene copolymer (hereinafter, referred to as FEP), TFE-hexafluoropropylene-vinylidene fluoride copolymer,
Examples include CTFE-ethylene copolymer, CTFE-perfluoro (alkyl vinyl ether) copolymer, CTFE-hexafluoropropylene-vinylidene fluoride copolymer, polyvinylidene fluoride, polyvinyl fluoride and the like. Among these fluororesins, especially ETFE, FE
P, PFA and TFE-hexafluoropropylene-vinylidene fluoride copolymer are preferred.

The fluororesin composition of the present invention preferably contains the composite particles in an amount of 0.4 to 10 parts by weight based on 100 parts by weight of the fluororesin. The amount of the composite particles to be blended is set in accordance with the performance of a coating material that blocks 50% or more of light having a wavelength of 330 to 360 nm and transmits 70% or more of light having a wavelength of 400 to 700 nm.

The method for forming the fluorescent lamp coating material of the present invention is not particularly limited, and a general hot melt kneading method can be employed. As an example, a mixture obtained by premixing a predetermined amount of the fluororesin and the composite particles in advance is supplied to an extrusion kneader having a kneading function, or the mixture is supplied from separate supply feeders, melt-kneaded, and melt-kneaded. Is obtained. The pellets can be formed into a fluorescent lamp covering material such as a film or a tube using an extruder.

Examples of the method of coating a fluorescent lamp include a method of coating the film on a fluorescent lamp tube and a method of coating a heat-shrinkable tube on a fluorescent lamp tube. As a method of coating the film on the fluorescent lamp tube, a method of winding the film around the fluorescent lamp tube and then bonding the ends of the films together, a method of winding the film around the fluorescent lamp tube with the fluorescent lamp tube and the film via an adhesive layer Etc. can be adopted.

For example, a heat-shrinkable tube is prepared by inserting a tube formed by using an out-molding machine into pellets into a heated mandrel, evacuating the space between the mandrel and the tube, heating the tube uniformly, and pressing air into the tube. Then, the tube is drawn uniformly. Then, the obtained heat-shrinkable tube is covered with a fluorescent lamp, and the tube is heated from the outside while evacuating the heat-shrinkable tube and the fluorescent lamp to obtain a fluorescent lamp covered with the tube.

The thickness of the coating material may be set in consideration of the application and the ultraviolet blocking performance. In order not to reduce the visible light transmittance of the fluorescent lamp, the coating material is preferably highly transparent. When the fluorescent lamp is broken, a thick one is preferable in order to prevent the fragments from scattering. Therefore, the thickness of the coating material is preferably in the range of 30 to 500 μm.

The light transmittance in the present invention is JIS-K
Determined by a measurement method based on 7105,
The total amount of diffuse light and parallel light, that is, the total light transmittance. The light source used in this method is based on JIS-Z8720 and includes standard light distributed in the range of 300 to 830 nm.

In the present invention, blocking 50% of light having a wavelength of 330 to 360 nm means blocking at least 50% over the entire wavelength range. Further, transmitting 70% or more of light having a wavelength of 400 to 700 nm means that 70% or more of light having a wavelength of
%.

[0033]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 Sodium bicarbonate was added while blowing carbon dioxide gas into a 20% by weight aqueous zinc chloride solution to obtain a slightly white slurry of zinc carbonate. The particle size of zinc carbonate is 0.
005 to 0.02 μm. After thoroughly washing the zinc carbonate with water, keep the temperature at 60 ° C. and stir with 20% by weight.
An ethanol solution of tetraethyl silicate was added dropwise to deposit amorphous silica on the surface of the zinc carbonate particles. The addition amount of tetraethyl silicate, compared carbonate 100 parts by weight of zinc, were added dropwise so that 100 parts by weight as SiO _2. Thereafter, stirring was continued for 1 hour or more, and finally, dilute nitric acid was added to neutralize the mixture, and the coating of zinc carbonate with amorphous silica was terminated. After washing, drying and pulverizing,
The mixture was calcined at 00 ° C. for 1 hour to obtain composite particles in which zinc oxide particles coated with amorphous silica were aggregated.

The composition of the composite particles is zinc oxide: Si
O ₂ = 100: 154 (weight ratio). When the particle size of the composite particles was measured with a laser diffraction / scattering particle size analyzer (manufactured by Seishin Enterprise, LMS-24), 95% of the particles were distributed in 0.1 to 30 μm, and the average particle size was small. The diameter was 7.8 μm.

200 g of the composite particles were charged into a small Henschel mixer, and subsequently, ethyltriethoxysilane 1
40 g of a solution obtained by dissolving 4 g of a mixed solution of water: methanol = 1: 9 (weight ratio) was slowly added thereto, followed by stirring for 10 minutes. Subsequently, the surface-treated wet composite particles were heated to 120 ° C.
For 1 hour and again thoroughly loosened with a small Henschel mixer for 2 minutes.

80 g of the composite particles were dry-mixed with 4 kg of ETFE (Aflon COP, C-88AX, manufactured by Asahi Glass) using a V mixer. This mixture is mixed with a twin screw extruder for 320
Pelleted at 0 ° C. Next, a tube having an outer diameter of 6 mm and an inner diameter of 5 mm was extruded from the annular die using a 30 mm single screw extruder. This tube was stretched at 150 ° C., and a fluorescent lamp tube having an outer diameter of 32 mm was inserted to prepare a tube-coated fluorescent lamp.

This coated tube was cut out, and its total light transmittance was measured using a spectrophotometer (Shimadzu Corporation, UV-300).
0), the total light transmittance at 330 to 360 nm was 9% or less, that is, 330 to 36.
The light of 0 nm was cut off by 91% or more, the total light transmittance at 400 to 700 nm was 80 to 88%, and the haze was 30%. FIG. 1 shows the total light transmittance.

Further, the tube-coated fluorescent lamp was exposed outdoors for 3 years, after which the exposed tube was partially cut, and the total light transmittance was measured. As a result, 330 to 360 nm
Is 11% or less, that is, 330 to
The light of 360 nm is blocked by 89% or more, and 400 to 700 n
m, the total light transmittance was 80 to 88%, and the haze was 32%. FIG. 1 shows the total light transmittance.

Example 2 (Comparative Example) A tube was prepared in the same manner as in Example 1 except that no composite particles were added, and a fluorescent lamp coated with the tube was prepared. FIG. 1 shows the result of measuring the total light transmittance of the film tube.

[0041]

The coating material of the present invention blocks ultraviolet rays having a wavelength of 360 nm or less and emits light having a wavelength of 400 to 700 nm by 70%.
It transmits above and is excellent in durability.

[Brief description of the drawings]

FIG. 1 is a chart of the total light transmission of the coating materials of Example 1 (including after three years of exposure) and Example 2.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 Z 127/12 127/12 // C09K 3/00 104 C09K 3/00 104Z F21V 9/06 F21V 9/06 (72) Inventor Yuji Tanonaka 3-474, Tsukakoshi, Koyuki-ku, Kawasaki-shi, Kanagawa F-term in Asahi Glass Co., Ltd. F-term (reference) 4J002 BD121 BD141 BD151 BD161 DE106 FB076 FB096 GQ00 4J038 CB031 CD091 CD111 CD121 CD131 CE051 HA216 KA15 KA20 NA19 PB09 PC03

Claims (6)

[Claims] 1. A fluororesin composition for covering a fluorescent lamp, comprising composite particles obtained by assembling zinc oxide particles coated with amorphous silica. 2. Composite particles having a particle diameter of 0.1 to 30 μm, wherein the composite particles are formed by assembling zinc oxide particles coated with 20 to 200 parts by weight of amorphous silica with respect to 100 parts by weight of zinc oxide. The fluororesin composition according to claim 1, which is: 3. The fluororesin is a tetrafluoroethylene homopolymer, a chlorotrifluoroethylene homopolymer, a tetrafluoroethylene-ethylene copolymer, a tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer, a tetrafluoroethylene. -Hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, chlorotrifluoroethylene-ethylene copolymer, chlorotrifluoroethylene-perfluoro (alkyl vinyl ether) copolymer, chlorotriene The fluororesin composition according to claim 1 or 2, which is a fluoroethylene-hexafluoropropylene copolymer or a chlorotrifluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer. 4. A fluorescent lamp covering material comprising a film or a tube of the fluororesin composition according to claim 1, 2 or 3. 5. The coating material blocks 50% or more of light having a wavelength of 330 to 360 nm and blocks light having a wavelength of 400 to 700 nm.
The fluorescent lamp coating material according to claim 4, which is a coating material that transmits 0% or more. 6. A fluorescent lamp coated with the fluorescent lamp coating material according to claim 4.